Javier Tejada Palacios (January 6, 1948, Castejón, Navarra) is a physicist and scientist specializing in quantum magnetism. He is currently Professor of Condensed Matter Physics at the Faculty of Physics of the University of Barcelona and director of the Laboratory UBX. He has developed his professional and academic background in German, French, British, American, and Spanish universities. He has published over 300 papers in international journals whose citations amount to 10354. He has also published 200 articles in Spanish newspapers and has written textbooks on magnetism and popular/divulagative science books. He has been invited to 108 international conferences in various universities and research centers, as well as 24 conference in Spain. He has 18 international patents and has conducted 30 projects of basic research, applied research, 20 companies, 17 theses and 31 doctoral theses. Among his most important scientific achievements include the first experimental evidence of tunneling of the magnetization, the discovery of resonant tunneling spin, the discovery of quantum spin coherence, and the discovery of magnetic deflagration quantum. His scientific work has been recognized with several national and international awards and he is a member of various European and American scientific societies.

Flipping spins spread like wildfire

news

20/05/2013
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Tim Wogan

New research into how local heating sets off a chain reaction of magnetic domain reversal could provide important insights into how wildfires spread. That is the conclusion of scientists in the US and Spain, who have pinpointed with greater precision than ever before the conditions under which such a magnetic deflagration will occur. The results could provide insights into runaway chemical reactions and even forest fires.

In 1771, the young Spanish painter Francisco Goya travelled to Rome to learn and be inspired by the many great artists there. In that year, he is thought to have painted “The Sacrifice to Vesta” depicting a sacrifice to the goddess of fire. The work is important because it shows how Goya was developing artistically at a formative stage in his career.

There is little dispute that Goya is the author of this work– the artist’s skill and style are clear and various experts have confirmed the attribution. However, the painting lacks a signature, a feature that would leave nothing to debate.

Today, Cristina Seco-Martorell at the University of Barcelona in Spain and a few buddies say they have discovered Goya’s signature hidden behind a layer of varnish in the picture. And the trick they used to make this discovery is an entirely type of analysis using terahertz waves.

Viewpoint: Fire in a Quantum Mechanical Forest

news

13/05/2013
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Je-Geun Park & Carley Paulsen

In a magnetized material, a phenomenon akin to an avalanche can sometimes occur: one spin, or perhaps just a few, can suddenly flip, and thereby spark a cascade of spin flips that fully reverses the sample magnetization. Such “magnetic avalanches” have been observed in a wide variety of systems at low temperature (such as ferromagnets, superconductors, as well as disordered systems like spin glasses and spin ices). These phenomena are sometimes considered a nuisance, since they may lead to instabilities that are detrimental to experiments and applications. Yet they can be the manifestation of complex quantum-mechanical effects and may offer a controllable platform to study other avalanche processes, such as the propagation of combustion in a material on fire. In Physical Review Letters, Pradeep Subedi, at New York University, and colleagues report on a new way to control and measure such avalanches in Mn12-acetate [1], a prototypical molecular nanomagnet.